Prior art patent documents 1 to 5 below disclose series hybrid vehicles, respectively.
According to a conventional engine control for such a series hybrid vehicle, a necessary drive and an operation that supplies power to be consumed to an air conditioner, etc., are performed through a fixed-point operation (an operation that makes an accelerator pedal opening degree not associated with an engine speed) mainly at a maximum efficiency point or in accordance with the accelerator pedal opening degree completely.